1. Field of the Invention
The present invention relates to a battery pack apparatus including a battery pack having a plurality of rechargeable batteries and a control section for controlling the charge and discharge of the battery pack.
2. Description of the Related Art
In a battery pack having a plurality of rechargeable batteries, the battery temperature tends to rise due to heat generation caused by charge and discharge of the batteries, which induces decrease of the battery output, the charge/discharge efficiency and the battery lifetime. To cope with such problem, it has been conventionally known that a battery pack apparatus includes a battery pack composed of a plurality of rechargeable batteries arranged in parallel, with cooling medium passages interposed therebetween and a device for feeding cooling medium through the cooling medium passage.
As another known apparatus, FIG. 4 shows a configuration of a battery pack apparatus in which a combination of such a battery pack and a cooling medium feeding device is further provided with a control section for controlling the charge and discharge of the battery pack. Referring to FIG. 4, a battery pack arrangement space 32 and a control section arrangement space 33 are set side by side along a longitudinal direction inside a case 31, and a battery pack 34 is disposed in an inclined posture in the battery pack arrangement space 32. A cooling medium feeding device 36 is connected to one end of a feeding space 35 that is defined between one side face of the battery pack 34 and the opposing wall of the case 31. A discharging space 37 is defined between another side face of the battery pack 34 and the opposing wall of the case 31, and an end of this discharging space 37 is connected to one end of a discharging passage 38 provided in the control section arrangement space 33 while the other end of the discharging passage 38 is opened to the outside of the case 31. Further, there is provided, in the discharging passage 38, a cooling fin 40 thermally coupled to a control section 39 arranged within the control section arrangement space 33 for performing heat exchange with cooling medium (see Japanese Patent Laid-Open Publication No. Hei 11-180168, for example).
However, in a battery pack apparatus such as disclosed in Japanese Patent Laid-Open Publication No. Hei 11-180168, the discharging passage 38 in the control section arrangement space 33 must be completely sealed to prevent cooling medium from entering the control section arrangement space 33. Otherwise, hydrogen gas or alkali mist emitted from the battery pack 34 or dust or similar will enter the control section 39 to cause adverse effects. Further, according to this conventional configuration in which heat from the control section 39 is dissipated to the cooling medium by means of the cooling fin 40, the heat transfer efficiency is low and hence the cooling efficiency is poor. Additionally, the provision of the cooling fin 40 increases the weight and cost.